1. Field of the Invention
The present invention relates to a magnetic resonance system, of the type having a cylindrical patient support unit in the form of a chamber delimited by a wall with a patient bed, as well as at least one flexible flat local coil element with at least one local coil.
2. Description of the Prior Art
In modern magnetic resonance systems local coils are used as reception coils in order to obtain a better resolution of images by placing them closer to the patient. for this purpose, the practice of laying the local coils directly on the patient is known. Since the coils can be placed close to the patient in this way, a high signal-to-noise ratio (SNR) is achieved. Disadvantageously, however, the process of attaching the coils to the patient is a very complex one. There is also the fact that multi-pin plug-in connections are used which are mechanically very delicate.
In a further solution local coils to be plugged into the patient bed are provided. Mountings of different sizes and in different positions, however, must be available to bring the coils very close to the patient and thereby achieve a high SNR. Again, a certain installation or de-installation time is required. Here as well the coil connectors are mechanically strained.
In other known magnetic resonance systems local coils are provided that are fixed behind the cladding, which are usually as used as the transmission antenna. As a result of their large distance from the patient, only a very low SNR is achieved, particularly in the case of slim patients for whom the antenna is far removed from the body.
United States Patent Application Publication No. 2002/0138001 A1 proposes installing a rigid local coil or local coil arrangement within the patient support unit. An actuator can be used to lower the local coil arrangement from above down onto the patient. This does not achieve good positioning on the patient. Furthermore, significant space is required for the actuator.
U.S. Pat. No. 5,548,218 discloses a local coil arrangement which has flexible wings which can be laid over a patient's body. Such a local coil arrangement, however, must first be attached to the patient.